Just in the case the linked article disappears and anyone needs it ... here is the list with all the extensions that are enabled by default (copied from the mentioned article):
composer.json
{
"require": {
"php-64bit": "~5.6",
"ext-amqp": "*",
"ext-bcmath": "*",
"ext-bz2": "*",
"ext-calendar": "*",
"ext-dba": "*",
"ext-exif": "*",
"ext-ftp": "*",
"ext-curl": "*",
"ext-gd": "*",
"ext-gettext": "*",
"ext-imagick": "*",
"ext-intl": "*",
"ext-mbstring": "*",
"ext-mcrypt": "*",
"ext-memcached": "*",
"ext-mongo": "*",
"ext-mssql": "*",
"ext-mysql": "*",
"ext-mysqli": "*",
"ext-mysqlnd": "*",
"ext-newrelic": "*",
"ext-oauth": "*",
"ext-pdo": "*",
"ext-pdo_dblib": "*",
"ext-pdo_mysql": "*",
"ext-pdo_pgsql": "*",
"ext-pdo_sqlite": "*",
"ext-pgsql": "*",
"ext-shmop": "*",
"ext-soap": "*",
"ext-sockets": "*",
"ext-sqlite3": "*",
"ext-sysvmsg": "*",
"ext-sysvsem": "*",
"ext-sysvshm": "*",
"ext-wddx": "*",
"ext-xmlrpc": "*",
"ext-xsl": "*",
"ext-zip": "*",
"ext-zlib": "*"
}
}
Note: There is also a PHP info available which contains the corresponding extension configuration for the default Pinky stack: http://phpinfo.cloudcontrolled.com/